Sir Paul McCartney, Bruce Springsteen, Dave Grohl and Billy Joel all signed Fender guitars during the epic 12-12-12 Concert for Sandy Relief in New York to raise even more money for charity. All of the headline acts from Wednesday’s star-studded show, including Eric Clapton, Jon Bon Jovi and Alicia Keys, autographed 10 different Fender guitars to boost funds for the event’s charity, The Robin Hood Foundation. The guitars have so far raised $202,250 on the Charitybuzz.com website and are expected to bring in more than $500,000 by the time bidding closes next Wednesday. The auction proceeds will add to the estimated $32 million already raised from the event’s ticket sales and donations to help those affected by superstorm Sandy, which ravaged East Coast in October.